F
v
=
mix i
F
F
v
= 887,9344
4433,3748 F
v
= 4,99291 m
3
jam Keterangan:
ρ
mix
= densitas campuran kg m³ F
i
= laju alir massa kgjam F
v
= laju alir massa m³ jam
c.
Perancangan Bejana Netralizer
1. Menentukan Volume Cairan
Waktu tinggal : 10 menit Arthur Chan, 2004 =
o cairan
V V
Dimana V
o
= F
v
, maka: V
cairan
= F
v
× V
cairan
= 6,99291 m
3
jam × 0,1667 jam V
cairan
= 0,832151 m
3
= 29,3528 ft
3
Keterangan: = waktu tinggal jam
V
cairan
= volume cairan dalam netralizer m
3
V
o
= F
v
= laju alir massa m
3
jam Maka volume cairan
Over design factor : 20
Peter and Timmerhaus, 4rd ed. pp.37
V
desain
= 1,2 x V
L
= 1,2 x 0,83215 m
3
= 0,99858 m
3
= 35,22333 ft
3
V
netralizer
= V
L
,
shell
+ V
dh,b
+ V
sf,b
V
L
,
shell
= volume cairan dalam shell =
4 H
D
L 2
i
V
dh
= volume dish head dalam satuan ft
3
dan D
i
, diameter shell bagian dalam satuan inchi Eq.5.11 daat dituliskan
= 0,000049D
i 3
B Y, Pers 5:88 V
sf
= volume straight flange =
4 sf
D
2 i
sehingga, V
L
=
4 H
D
L 2
i
+ 0,00004912D
i 3
+
4 sf
D
2 i
sf = 2 in = 0,1667 ft
Diambil H
L
= D
i
Mc Cabe, 1985; Geonkoplis,1994; Walas,1988; Brownell, p43, 1959
30.6934 ft
3
=
4 D
3 i
+ 0,00004912D
i 3
+ 4
1667 ,
2 i
D D
i
= 3,0757 ft = 0,9375 m = 36,9086 in H
L
= 3,0757 ft = 0,9375 m = 36,9086 in
2. Tekanan desain
P
operasi
= 1 atm = 14,6959 psi
P
hid.
=
144 h
g g
.
L c
mix
ρ
mix
= 887,9344 kg m
3
= 55,4301 lbft
3
Keterangan : g = Percepatan gravitasi = 32,174 fts
2
g
c
= Faktor konversi percepatan gravitasi = 32,1740 g
m
.cmg
f
.s
2
P
hid.
= 144
3,0757 x
1 x
55,4301
3
ft
ft lb
= 1,1839 lbin
2
= 1,1839 psi
Tekanan desain 5 -10 diatas tekanan kerja normal Couldson, vol.6, 1983, pp.637
Tekanan desain diambil 10 diatasnya. P
design
= 1,1 P
operating
+ P
hid.
= 1,1 14,6959 psi + 1,1839 psi = 17,46782 psi
3. Ketebalan Dinding Bejana
Ketebalan dinding shell : C
p E
f r
p t
d i
d s
. 6
, .
. Brownell, 1959, pers.13.1:254
dengan : t
s
: ketebalan dinding shell, in p
d
: tekanan desain, psi d
i
: diameter shell bagian dalam , in f
: nilai tegangan material, psi Brownell, 1959, App. D, p 335 digunakan material SA-167 Grade11 Type 316, f = 18.750 psi
pada 104 °F E
: efisiensi sambungan, dengan radiograp spot : 0,80 Jenis sambungan las : single-butt weld dengan backing stripe
Brownell, 1959 .Tabel 13.2 C
: korosi yang diizinkan corrosion allowance = 0,125 in
r
i
= D
i
2 = 36,9086 in 2 = 18,4543 in t
s
= in
psi psi
in psi
125 ,
17,4678 x
6 ,
80 ,
x 18750
4543 ,
18 x
17,4678
= 0,1465 in 0,1875 in
Digunakan tebal dinding standar: t
s
= 316 in = 0,1875 in
Ketebalan torisherical head
C p
2 .
E f
2 W
r p
t
d c
d d
Brownell, 1959 pers.7.77
l c
r r
3 4
1 W
Brownell, 1959 pers.7.76
Keterangan : W
: stress-intensification factor for torispherical dish r
c
: crown radius = dish radius, in r
i
: knuckle radius = inside corner radius, in OD
= ID + 2 t
s
= 36,9086 in + 2 x 0,1875 in = 37,2836 in
Dari tabel 5.7 Brownell dan Young, untuk OD 40 in diperoleh r= 40 in dan r
icr
= 2,5 W
=
5 ,
2 40
3 4
1
= 1,750 t
d
= in
psi psi
x in
psi 125
, 17,4678
x 2
, 80
, x
18750 2
750 ,
1 x
40 x
17,4678
= 0,1658 in digunakan tebal head standar = 316 in = 0,1875 ft
Dari Tabel 5.8 Brownell and Young, 1959 diperoleh sf = 1
2 1
- 2 in. Digunakan straight flange s
f
= 2 in Brownell Young, table 5.8:93
4. Tinggi Bejana
Tinggi shell, Hs = 3,0757 ft Tinggi dish, dihitung dengan dimensi berikut:
